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Author: a) H.S. Choi, b) J.G. Bomba

a) Department of Naval Architecture and Ocean Engineering, Pusan National University, Pusan 609-735, South Korea
b) R J Brown Deepwater Inc., 11700 Old Katy Road, Suite 150, Houston, TX 77079, USA
Received 27 June 2002; received in revised form 18 October 2002; accepted 23 October 2002

Abstract:

     The purpose of this paper is to establish acceptance criteria for interpretation of the internal inspection results of undersea pipelines. There are no specific rules or guidelines for the acceptance criteria of existing pipelines using a certain internal inspection method. Acceptable criteria were established with a case study of a 609.6 mm (24 in.) diameter, concrete weight coated pipeline delivers fuel oil to a thermal power plant, Ghana. Parameters to be considered in the uncertainties of flaw sizing include the crack length, depth, orientation of the flaw, whether or not the flaw is surface breaking, and number of flaws. Fitness-for-services of other pipelines can be determined using the established criteria in this study. The method of inspection also affects the acceptance criteria. Imposing limitations at or beyond the limits of detection capability would obviously be counter-productive.

Keywords: Acceptance criteria; Pipeline; Internal inspection; Corroded pipe; Defects; Dent; Crack

Corresponding author. Tel.: +82-51-510-2343; fax: +82-51-512-8836.
E-mail address: hanchoi@pusan.ac.kr (H.S. Choi).

Abbreviations:
ABS, American Bureau of Shipping; API, American Petroleum Institute; ASME, American Society of Mechanical Engineers; DNV, Det Norske Veritas; MAOP, maximum allowable operating pressure; PLEM, pipeline end manifold; PRCI, Pipeline Research Council International, Inc.; RTD, Rontgen Technische Dienst; SMYS, specified minimum yield strength; SPM, single point mooring; VRA, Volta river authority